Revisiting Controls on Shale Oil Accumulation in Saline Lacustrine Basins: The Permian Lucaogou Formation Mixed Rocks, Junggar Basin

Table 1

Classification of lithofacies in the Lucaogou Formation, Jimusar Sag.

Main categories of lithofacies			Subcategories and specific types of lithofacies
(A) Intrabasinal sedimentary rocks	(a) Carbonate rock		(1) Obvious laminae: laminated silty dolomite (rarely observed)
			(2) No obvious laminae but may have obvious algae or biological disturbance: massive dolarenite, massive silty dolomite, massive argillaceous dolomite, massive dolomicrite (commonly observed)
(B) Terrigenous elastic rocks	Mudstone	(b) Dolomitic/calcareous mudstone	(3) Obvious laminae: laminated (silt/tuff-bearing) dolomitic/calcareous mudstone (rarely observed); (4) No obvious laminae: massive(silt/tuff-bearing) dolomitic/calcareous mudstone (commonly observed)
		(c) Tuffaceous/silty mudstone	(5) Obvious laminae: laminated (dolomized) tuffaceous/silty mudstone, shale (commonly observed); (6) No obvious laminae: laminated (dolomized) tuffaceous/silty mudstone (rarely observed)
	(d) Siltstone		(7) Obvious laminae: laminated calcareous/dolomitic/tuffaceous/argillaceous siltstone (rarely observed); (8) No obvious laminae: massive calcareous/dolomitic/argillaceous siltstone (commonly observed)
(C) Volcanic-sedimentary clastic rocks	(e) Tuffaceous rock (rare)		(9) Tuffite, tuff, and dolomitic tuff